As Rita walked towards the station she drew her coat around her. It was chilly and although she had got changed into other clothes, got cleaned up, she still felt damp from where Jon had spilled her lime and soda. She knew she hadn't seen the last of the guy. The anxiety she felt about that was tinged with frustration as she played the recording of their conversation back on her headphones, blocking out the street noises around her.

Despite his histrionics Jon hadn't told her anything substantive, apart from that he was a misogynistic creep with a thin skin and a tendency to gaslight women - but she had known that already. Rage and contempt dripped from his voice on the recording. She had no more answers to Erica's murder, but weirdly, it was a relief that Jon sounded as creepy and unhinged out of the moment as in it.

He had drawn attention to himself with his tantrum. He was on that barman's radar if nothing else.

There was a kiosk outside the station selling hot drinks. The air had turned frigid again and a wind whipped up her hair. It got dark too soon here and the sun was already starting to drop in the clouded sky.

'I'll have a red berry tea, please,' she said. In the corner of her vision she saw a man sitting on the short stone wall next to the station. As the young woman behind the kiosk prepared the tea for her, Rita looked over at the man and her stomach tensed in irritation. She wasn't surprised Jon had gone after her.

Men like him were like that.

'Here's your tea. Have a good day,' the girl smiled. Rita smiled back. She took the hot paper cup in both hands, then hastily put it on the ledge and reached for a cardboard ring to take the sting out of its temperature. The girl looked at her sympathetically. 'Yeah, they can be a bit hot. Sorry.'

'Not a problem,' Rita said, turning away. Her train back down to London wasn't for another 45 minutes. She gazed at the automatic doors, constantly sliding back and forth as passengers went in and out. She thought of Jon sitting a few seats behind her on the train and it made her sick to imagine. It reminded her of the stalker she'd had at police college and the other creepy men - and one woman - who had hassled her when she was younger. One advantage of being 44 was, so she'd thought, that she didn't have to deal with any of that any more, but apparently that wasn't the case. When she glanced at him again, he looked away. 'Maldito cobarde,' she muttered under her breath. She opened the recording app on her phone and pressed play.

Then, she walked towards him and sat down a metre away. 'I thought you were visiting your dad.'

'Oh! It was a flying visit, you know how these things are.' Jon looked twitchy and nervous. 'From today, he's...looking after a friend's dog while they are on holiday, so I've been kicked out to roam. The dog is a rescue. Skittish around new people. Sensitive natures, many animals have, don't they? You must have gone through this with Pepelito. You understand.'

'I am not sure I do.' She spoke slowly, her jaw tightening at the fact he was even thinking about Pepelito. 'Why have you followed me here?'

'Look...I have to apologise, Rita, for my behaviour earlier. It was completely uncalled for. I lost control. It's the stress of Erica's murder. I know I'm under suspicion and - and that conversation just felt like being interrogated for my wife's death all over again. It brought back some traumatic memories.'

Not as traumatic as it was for your wife, Rita thought. 'OK. Well, I'm glad you're here. There are a few other things I want to ask you.' After a pause, she added, 'If you're feeling up to it.'

'Sure,' Jon said. 'You can ask me anything, Rita.' He spoke so casually and sincerely it was unnerving. 'But it's cold here. It's going to rain. Do you want to get a drink?'

She hadn't mentioned meeting him when she had left Aimee and Heather's house earlier. They'd both have tried talking her out of it and they'd have been absolutely right.

Maybe she should have done.

'It's on me. I'm so sorry. The last thing I wanted to do is hurt you.'

'No, let's stay here,' Rita said. 'Google says it won't rain for two hours.'

'Oh shit. I've messed up big time.' His tone was awkward and apologetic and if it had been anyone else she might have given him the benefit of the doubt. He'd been lovely at first, Aimee had said. He'd have to be to charm all those women.

'Doesn't matter,' Rita said. 'It's a long shot, but I'd like to trace Sandra's address. Do you know where she lives?'

'After Frances...' Jon adopted a pained expression. 'Sandra moved back to Whitstable, I believe she wanted to be as far from me as possible, and it was her childhood home. I don't have her address, but last I heard, her mother was in a care home there. Unfortunately Sandra alienated herself from any other support. But she's deeply troubled. You saw what she was like. I wouldn't want to cause her any further distress.' He sighed. 'She's never forgiven me for my failings. I should have been a better husband to Frances and she blames me.' He sucked in a breath. 'You can't - you can't really believe what she says.'

'I'll be the judge of that.' Rita pursed her lips thoughtfully. 'Which care home was it?'

'Rose Place, or Tulip House. Something like that, I think. Something floral.' Jon shuffled uncomfortably. 'Look. I really am sorry. Let me make it up to you.'

A group of teenagers strolled towards the entrance of the station with their bikes. One of them looked at Rita and she smiled at the boy, who nodded at her awkwardly. Her tea was almost cool enough to drink. Turning back to Jon, she said gently, 'Thank you. You can make it up to me by telling me about Elizabeta Krasovskaya. She was a contemporary of yours, wasn't she?'

Jon's body startled. It was like he'd been given a physical shock. He stared at Rita, his foot drumming on the ground, his face paling in front of her eyes. 'Sorry. What did you say?'

'Elizabeta Krasovskaya,' Rita said. A tiny drop of rain fell on her coat. She brushed it off. 'The Russian student who went missing. You attended the same university in 2006. Aimee met her. Did you?'

'I...don't know. Don't think so. If I did, I have no idea.' He spoke too quickly for Rita to be convinced. His reactions contrasted with his raw rage in the pub and the overconfident, resentful arrogance he'd displayed elsewhere. He attempted a dismissive, unconvincing laugh. 'I'm afraid I don't recall her. There were thousands of students and at the time, I was finishing my PhD. I can't be expected to know every single person.' He sighed. 'Look - Rita - I'm sure you don't remember everyone you arrest. Same sort of deal. Isn't it?'

'I'd remember if someone I'd dealt with professionally vanished under such circumstances,' Rita said, feeling queasy. 'But you had a lot going on back then, I'm sure.'

'Listen,' Jon said, his face an off white colour, like he was about to be sick. 'I've just seen the time. I should make a move. I have to get back to Cambridge.'

'Fine,' Rita said, but Jon had already got up. She watched him head into the train station, walking straight for the automatic doors without turning round.